i. Pathogenesis of Periodontal Disease
Periodontal disease encompasses a group of different disorders which affect the gums or supporting structures of the teeth. The general epidemiology of plaque associated periodontal disease typically begins with the formation of supragingival microbial plaque which, if left untreated, subsequently invades the normally closed space between the free gingiva and the tooth surface. If left unremoved, such subgingival plaque gives rise to the formation of hardened calculi and areas of erosion on the subgingival surfaces of the tooth (i.e. the subgingival enamel and root surfaces). Resultant inflammation of the surrounding tissues and recession of the surrounding connective tissue and bone then occurs. Such inflammation and recession of the periodontia results in the formation of a gap or "periodontal pocket" between the gingival tissue and the adjacent tooth surface. The gradual loss of ligamentous attachment and surrounding alveolar bone mass in periodontal disease often results in loss of the affected tooth, unless effective treatment is administered to halt the progression of the disease.
Clinically, plaque associated periodontal disease may be treated by either a surgical or nonsurgical approach.
The surgical approach to the treatment of plaque associated periodontal disease typically involves the performance of one or more surgical procedures whereby the gingival tissue is excised and the underlying tooth surfaces (e.g. subgingival enamel and a portion of the root) are visually examined and subjected to scaling and root planing under direct visualization. Although the surgical approach to the treatment of plaque associated periodontal disease is often highly effective, such surgical approach is also associated with significant expense and a significant degree of patient discomfort.
The nonsurgical approach to the treatment of plaque associated periodontal disease typically involves procedures known as subgingival scaling and root planing. Some chemical formulations for dissolving and/or removing subgingival plaque and/or calculus are also known. Subgingival scaling and root planing procedures are typically accomplished by inserting a hand instrument, an ultrasonic or sonic cleaning device and/or a rotating instrument into the periodontal pocket (PP), without cutting or excising the gingiva, for the purpose of scraping plaque or dental calculus from the subgingival tooth surfaces. The ultimate effectiveness of such subgingival scaling and root planing procedures, or chemical plaque/calculus removal methods, is dependent upon the completeness with which removal of plaque or calculi has been effected by such procedures. Because the surrounding gingiva remain intact, the operator is unable to directly view the subgingival tooth surfaces when carrying out such subgingival plaque and calculus removal procedures. The inability to visualize the subgingival tooth surfaces makes it virtually impossible for the operator to ascertain whether all of the subgingival plaque or calculus has been effectively removed. Failure to completely remove all subgingival deposits of plaque or dental calculus may result in progression of the periodontal disease. Such progression of the disease often necessitates abandonment of the nonsurgical treatment approach in favor of the more costly and painful surgical approach.
In view of the desirability of treating periodontal disease by nonsurgical treatment modalities, there exists a need in the art for new devices and techniques whereby the subgingival tooth surfaces may be endoscopically viewed to permit visual assessment and/or guidance of subgingival plaque/calculus removal procedures without the need for surgical cutting or excision of the gums.
Additionally, there exists a need in the art for endoscopically viewing the subgingival tooth surfaces and/or subgingival tissues of the periodontium during and/or after various treatment procedures directed at the subgingival tooth surfaces and/or subgingival tissues. Examples of treatment procedures which may guided, monitored, visualized and/or assessed by direct endoscopic viewing include (a) resection of subgingival granulation tissue, (b) alveolar bone seeding or bone grafting procedures, and (c) the application of chemical agents to the subgingival root surfaces to facilitate new ligamentous attachment thereto.